1. Field of the Invention
The present invention relates to a composite electronic component including a resistance element and another electronic element, and a resistance element for use in the composite electronic component.
2. Description of the Related Art
Conventionally, there have been proposed inventions of composite electronic components including a plurality of electronic elements from the view point of integrating the electronic components with high density.
For example, JP-A 2001-338838 discloses a composite electronic component including a capacitor element and a resistance element. In this composite electronic component, a resistance element consisting exclusively of a resistor is disposed on the surface of a capacitor body of a chip capacitor. On the surface of the capacitor body, a pair of external electrodes is provided, and the external electrodes are connected with the resistor.
JP-A 6-283301 discloses a composite electronic component in which among two or more kinds of electronic elements selected from a plurality of kinds of electronic elements including a chip resistance, a chip thermistor, a chip capacitor and a chip varistor, electronic elements of the same shape and the same dimension are integrated. In this composite electronic component, these electronic elements are overlapped along the thickness direction, and respective terminal electrodes provided in these electronic elements are collectively covered with a lead frame to integrate the same.
The present inventors proposed in Japanese Patent Application No. 2015-049457 (U.S. patent application Ser. No. 15/042,236) a composite electronic component capable of improving the degree of freedom in circuit design compared with those disclosed in JP-A 2001-338838 and JP-A 6-283301. The composite electronic component is a novel composite electronic component including one substrate-type electronic element in which an insulating base portion functioning as a substrate is provided with a resistance function, and another electronic element joined with the substrate-type electronic element.
In the novel composite electronic component, the upper surface of the insulating base portion of the substrate-type electronic element faces another electronic element. On this upper surface, an upper surface conductor is disposed, and the upper surface conductor and an external electrode of another electronic element are connected via a joint material. In one preferred embodiment of the composite electronic component including a novel structure, a functional portion in addition to the upper surface conductor is provided on the upper surface of the insulating base portion of the substrate-type electronic element. The functional portion includes a resistor, other upper surface conductor connected with the resistor, and a protective film to protect the resistor.
When the substrate-type electronic element includes the functional portion on the upper surface, the functional portion can possibly come into contact with the other electronic element in mounting the other electronic element on the substrate-type electronic element. As the functional portion comes into contact with the other electronic element, the external electrode of the other electronic element becomes more distant from the upper surface conductor of the substrate-type electronic element, and as a result, insufficient joining between the substrate-type electronic element and the other electronic element, a so-called defective joining can occur.